An Overview and Comparison by Dr. David Lewis Anderson
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An Overview and Comparison by Dr. David Lewis Anderson
|Since the 1930’s, physicists have speculated
about the existence of "wormholes" in the fabric of space. Wormholes are hypothetical areas of warped
spacetime with great energy that can create tunnels through
spacetime. if traversable would allow a traveler to quickly move
through great distances in space and also travel through time.
The difficulty lies in keeping the wormhole open while the
traveler makes his journey: If the opening snaps shut, he will
never survive to emerge at the other end.
For years, scientists believed that the transit was physically impossible. But recent research, especially by the U.S. physicist Kip Thorne, suggests that it could be done using exotic materials capable of withstanding the immense forces involved. Even then, the time machine would be of limited use – for example, you could not return to a time before the wormhole was created. Using wormhole technology would also require a society so technologically advanced that it could master and exploit the energy within black holes.
Spacetime can be viewed as a 2D surface (to simplify understanding) that, when 'folded' over, allows the formation of a wormhole bridge. A wormhole has at least two mouths that are connected to a single throat or tube. If the wormhole is traversable, then matter can 'travel' from one mouth to the other by passing through the throat. While there is no observational evidence for wormholes, spacetime containing wormholes are known to be valid solutions in general relativity.
The term wormhole was coined by the American theoretical physicist John Archibald Wheeler in 1957. However, the idea of wormholes had already been theorized in 1921 by the German mathematician Hermann Weyl in connection with his analysis of mass in terms of electromagnetic field energy.
This analysis forces one to consider situations...where there is a net flux of lines of force through what topologists would call a handle of the multiply-connected space and what physicists might perhaps be excused for more vividly terming a ‘wormhole’.
The key characteristics of the application of wormholes for time control and time travel are presented in the picture below. This is followed by more detail describing the science below.
DefinitionThe basic notion of an intra-universe wormhole is that it is a compact region of spacetime whose boundary is topologically trivial but whose interior is not simply connected. Formalizing this idea leads to definitions such as the following, taken from Matt Visser's Lorentzian Wormholes.
If a Minkowski spacetime contains a compact region Ω, and if the topology of Ω is of the form Ω ~ R x Σ, where Σ is a three-manifold of nontrivial topology, whose boundary has topology of the form dΣ ~ S2, and if, furthermore, the hypersurfaces Σ are all spacelike, then the region Ω contains a quasi-permanent intra-universe wormhole.
Characterizing inter-universe wormholes is more difficult. For example, one can imagine a 'baby' universe connected to its 'parent' by a narrow 'umbilicus'. One might like to regard the umbilicus as the throat of a wormhole, but the spacetime is simply connected.
Before the stability problems of Schwarzschild wormholes were apparent, it was proposed that quasars were white holes forming the ends of wormholes of this type.
While Schwarzschild wormholes are not traversable, their existence inspired Kip Thorne to imagine traversable wormholes created by holding the 'throat' of a Schwarzschild wormhole open with exotic matter (material that has negative mass/energy).
Wormholes connect two points in spacetime, which means that they would in principle allow travel in time, as well as in space. In 1988, Morris, Thorne and Yurtsever worked out explicitly how to convert a wormhole traversing space into one traversing time. However, it has been said a time traversing wormhole cannot take you back to before it was made but this is disputed.
For example, consider two clocks at both mouths both showing the date as 2000. After being taken on a trip at relativistic velocities, the accelerated mouth is brought back to the same region as the stationary mouth with the accelerated mouth's clock reading 2005 while the stationary mouth's clock read 2010. A traveler who entered the accelerated mouth at this moment would exit the stationary mouth when its clock also read 2005, in the same region but now five years in the past. Such a configuration of wormholes would allow for a particle's world line to form a closed loop in spacetime, known as a closed timelike curve.
MetricsTheories of wormhole metrics describe the spacetime geometry of a wormhole and serve as theoretical models for time travel. An example of a (traversable) wormhole metric is the following:
One type of non-traversable wormhole metric is the Schwarzschild solution:
Concept of wormholes is used in The Wild Blue Yonder, a science fiction film by Werner Herzog.
The Massively Multiplayer Online Game EVE Online utilizes wormholes extensively as they are created in the use of the stargate technology which allows for interstellar travel in the game world.
The Vega Strike first-person space trading and combat simulator features wormholes to travel through star systems. The engine is open-source and has various mods and total conversions which have wormholes too, like Vega Trek, a Vega Strike mod based on the Star Trek universe. Or the Privateer Remake, a remake of Wing Commander: Privateer.
The 1979 Disney film The Black Hole's plot centers around a massive black hole, although it makes virtually no use of then-current worm-hole physics, with only one rather desultory mention of an Einstein-Rosen bridge. A trip through the black hole turns theological, abandoning scientific rationale.
Wormholes play major roles in the television series Farscape, where they are the cause of John Crichton's presence in the far reaches of our own galaxy, and in the Stargate series, where stargates create a stable artificial wormhole where matter is dematerialized, converted into energy, and is sent through to be rematerialized at the other side. In the latter series, the devices were discovered in Egypt by an archeologist, and were built by aliens known as the Ancients or the Alterans. In the science fiction series Sliders, a wormhole (or vortex, as it is usually called in the show) is used to travel between parallel worlds, and one is seen at least once or twice in every episode. In the pilot episode it was referred to as an "Einstein-Rosen-Podolsky bridge".
It is possible that the Webway technology used by the Eldar of the fictional Warhammer 40,000 could be perceived as wormhole technology.
In Command & Conquer 3 and in its expansion the Scrin faction (an alien life form with unknown origins from outer solar system) uses artificial wormholes for military purposes to convey infantry and vehicles behind enemy lines.
In the Invader Zim episode, "A Room with a Moose" Zim utilizes a wormhole to send his classmates into a parallel universe that consists entirely of a room with a large moose inside it.
The television series Strange Days at Blake Holsey High is about a wormhole the science club found at their school.
In an episode called "wormhole" in the 13th season of the long running American series Power Rangers, called Power Rangers SPD the spd rangers go through a wormhole to team up with the previous team of Power Rangers Dino Thunder from year 2004, after their enemy Emperor Grumm goes through one.
In the video game "Supreme Commander" the UEF faction utilizes aether-gates for long distance military strikes.
In the 1995-1996 FOX military science fiction series SPACE: Above and Beyond, during the first several episodes, the United Earth Force travel through wormholes, called the "Kali Region" or "Galileo Region" to arrive at exo-solar destinations. This idea is abandoned after the second episode.
In the movie Race to Witch Mountain the 2 aliens from a planet which is 3000 light years away from Earth use wormholes to travel to Earth.
In the 2009 Doctor Who Easter special, Planet of the Dead, the Doctor and a group of passengers aboard a double-decker bus are transported to an alien world via a wormhole.